The interaction of DPPA which is an important component in cellular membrane with molecules of water asmedia, cause some changes in geometry of DPPA .In this study we focused our attention on comparing thismolecule with related hydrated complexes employing different basis sets at hartree-fock levels of theory. Thetheoretical NMR shielding tensor of some imported atoms were also reported.

The structural properties of a new cyclic phosphor amide have been investigated in three methods and four basis sets and results have been compared with experimental data by spss. The best level for this type compound is HF/6-31++G** and with considering to this result, at this level, hyper chem input as initial geometry have been evaluated.

In this research, this possibility was investigated the relative stablilty geometry and bindingenergies of the hydrogen bonds of Molybdate-Phosphonic Acid (MPA) complex in gas phase onthe basis of result of ab initio and DFT calculations. Three DFT methods have been applied forcalculations are B3LYP, BP86 and B3PW91 that have been studied in two series of basis sets:D95** and 6-31+G(d,p) for hy...

Electron densities at nuclei are difficult to calculate accurately with all-Gaussian basis sets because they lack an electron-nuclear cusp. The newly developed mixed ramp-Gaussian basis sets, such as R-31G, possess electron-nuclear cusps due to the presence of ramp functions in the basis. The R-31G basis set is a general-purpose mixed ramp-Gaussian basis set modeled on the 6-31G basis set. The ...

A theoretical study of the kinetic and mechanism of intramoleccha cychcation of (1)-undeca-7,8-dien-2-yne was performed using MT methods at B3LYP and B3PW91 levels of theory using 6-311g, 6-311C.6-31 IGs*, 6-31I+G, 6-31 I4-SG and 6-3114H-Gs* basis seo. Equilibrium molecular geometries andharmonic vibrational frequencies of the reaccint, transition state and product wens calculated. Theconsidere...

Experimental and theoretical absorption spectra of [2-[2-[4-(dimethylamino) phenyl]ethenyl]-6-methyl-4H- pyran-4-ylidene]-propanedinitrile (DCM) have been studied. UV-Visible (UV-Vis.) absorption spectrum of DCM has been reported after its synthesis. Two relatively intense peaks appeared at 473 and 362 nm respectively. A theoretical investigation on the electronic structure of DCM is presented ...